Okay, after listening to his lines in scenario campaign, I'm convinced that it's definitely not Troy as Lei. I don't really hear him at all. Though it certainly sounds like him in his ending.

But on the bright side, I've discovered someone who could possibly be Lei's VA. I was checking the cast of Xenosaga, since it was also done by Cup of Tea (the recording studio for Tekken 6), and after listening to some clips of his voice, I think it might be Lex Lang. I'll go contact him to confirm this.